Steam and smoke clouds rise from a power plant factory in Huai'an city, East China's Jiangsu province, Jan 31. [Photo/CFP]

BEIJING -- China's environmental protection authorities dealt with 135 cases resulting from public tip-offs in October 2014, the Ministry of Environmental Protection said.

Of the cases, reported via the ministry hotline, 104 were found to concern illegal activities while 35 were cleared. Jiangsu Province had the most complaints with 14, followed by Guangdong, Henan and Shandong provinces.

Thirty-six cases were in chemical industry, 21 in processing and manufacturing and 10 in metallurgy.

Air pollution topped the list, followed by noise and water pollution.

The ministry said that the illegal activities had been dealt with in accordance with administrative regulations, including immediate corrections, stopping production, fines and closures.